<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>作用域</title>
</head>
<body>

</body>
</html>
<script type="text/javascript">
    for (var i = 0; i < 10; i++) {
        console.log(i);
    }
    console.log("变量污染：" + i);

    {
        let  par =0;
        console.log(par);
    }

</script>